The caries vaccine will never happen. It has been in the works (in some fashion) for over 40 years now, and each year we hear that it is getting closer and closer and that the future of dentistry, especially for GPs is looking grim because of it.
Remember, there are still people out there who "forget" to brush their teeth, "forget" to floss, and "forget" to cut back on sugars and other lovely treats.
Wiping out S. Mutans will only allow other bacterias to thrive in the mouth, and who knows what damage they might cause!
For hypothetical purposes, we can suppose that the vaccine does become available, that it works like a charm, and that everybody has access to it through a dentist or provider. Still, it is doubtful that insurance companies would pay for it the vaccine, if it ever does become available, and the majority of people won't take it anyways.
To make matters worse, there will always be a percentage of the population who cries "foul" when any type of vaccine or antibodies are introduced to the body. Whether or not to add flouride to water is still a raging debate in many states, and among many dentists. I also want to mention that there are still people (and quite a few!) who refuse to have their children vaccinated against any type of disease (chickenpox, MMR, etc.,) simply because they believe it is better to let the body develop its defenses naturally.
Further, if the largest % of oral damage comes from people who are too lazy to manage their own oral care, what makes us think they will suddenly seek out a caries vaccine from a provider?
The long and short of it is that the caries vaccine, if it ever comes to light (which I doubt it will), will NOT affect the future of dentistry signifigantly as we know it. Cavity damage is only a small fraction of the work that dentists do.
